Symmetric Cipher Model Quiz

<p>The attacker only has the ciphertext (C)</p> Signup and view all the answers

<p>168 bits (D)</p> Signup and view all the answers

<p>Both future and past messages are compromised (B)</p> Signup and view all the answers

<p>Chosen-plaintext attack (C)</p> Signup and view all the answers

<p>It compromises the confidentiality of messages (B)</p> Signup and view all the answers

<p>To find or know the plaintext of certain ciphertext portions (A)</p> Signup and view all the answers

<p>Chosen-ciphertext attack (B)</p> Signup and view all the answers

<p>Certain key words are known to be present in the message (B)</p> Signup and view all the answers

<p>Proneness to chosen-ciphertext analysis (C)</p> Signup and view all the answers

<p>They prioritize introducing basic concepts and terminology. (B)</p> Signup and view all the answers

<p>To transform plaintext into ciphertext (B)</p> Signup and view all the answers

<p>The same key is shared for both encryption and decryption (B)</p> Signup and view all the answers

<p>Cryptanalysis (C)</p> Signup and view all the answers

<p>The adversary knows everything about the system except the secret key. (D)</p> Signup and view all the answers

<p>Stream ciphers operate on data streams, while block ciphers operate on fixed-size data blocks. (C)</p> Signup and view all the answers

<p>They require different keys for various encryption processes. (A)</p> Signup and view all the answers

<p>Ciphertext and secret key (D)</p> Signup and view all the answers

<p>Y = E(K, X) (C)</p> Signup and view all the answers

<p>The attacker has access to some original messages and their encryptions. (C)</p> Signup and view all the answers

<p>Perform statistical analysis on the ciphertext. (D)</p> Signup and view all the answers

<p>It assists in the determination of how ciphertext is transformed. (B)</p> Signup and view all the answers

<p>An encryption scheme is insecure if it cannot resist ciphertext-only attacks. (A)</p> Signup and view all the answers

<p>Access to the original plaintext messages. (C)</p> Signup and view all the answers

<p>Statistical tests on the ciphertext. (A)</p> Signup and view all the answers

<p>When it cannot resist ciphertext-only attacks. (B)</p> Signup and view all the answers

<p>The same key is used for both encryption and decryption. (B)</p> Signup and view all the answers

<p>Cryptanalysis (D)</p> Signup and view all the answers

<p>The secret key used for encryption and decryption. (C)</p> Signup and view all the answers

<p>To recover the plaintext from ciphertext. (A)</p> Signup and view all the answers

<p>It is the same for both encryption and decryption processes. (C)</p> Signup and view all the answers

<p>Ciphertext-only attack (C)</p> Signup and view all the answers

<p>Common patterns in plaintext (D)</p> Signup and view all the answers

<p>Knowledge of plaintext associated with ciphertext (D)</p> Signup and view all the answers

<p>Patterns present in the plaintext (B)</p> Signup and view all the answers

<p>There is no predictable plaintext structure (B)</p> Signup and view all the answers

<p>Cryptanalytic attacks exploit characteristics of the algorithm. (A)</p> Signup and view all the answers

<p>Ciphertext-only attack (A)</p> Signup and view all the answers

<p>5.4 × 10^18 years (C)</p> Signup and view all the answers

<p>Both require knowledge of the encryption algorithm. (C)</p> Signup and view all the answers

<p>It typically requires trying half of the key space on average. (B)</p> Signup and view all the answers

A type of cipher where the same key is used for both encryption and decryption.

The process of converting plaintext into ciphertext.

The process of recovering plaintext from ciphertext.

The same key used for both encryption and decryption in symmetric ciphers.

A symmetric cipher that encrypts a fixed-size block of plaintext at a time.

The science of studying attacks against cryptographic systems.

The original message before encryption.

The encrypted message.

A method of attacking encryption that tries every possible key until the correct one is found.

A method of attacking encryption that exploits weaknesses in the algorithm rather than trying every key.

The number of bits used to represent a key.

The time needed for a brute-force attack increases exponentially with the key size.

A cryptanalytic attack where the attacker only has access to the ciphertext.

A cryptanalytic attack where the attacker has access to plaintext and corresponding ciphertext.

A cryptanalytic attack where the attacker can choose plaintext and get its corresponding ciphertext.

A cryptanalytic attack where the attacker can choose ciphertext and get its corresponding plaintext.

A type of known-plaintext attack where the attacker assumes certain words or phrases are likely to appear in the message, allowing them to use this knowledge to deduce the encryption key.

Classical encryption techniques aim to introduce basic concepts and terminology of encryption.

Classical encryption techniques prepare us for understanding modern cryptography.

Repetitive or predictable patterns that may appear in plaintext messages, which can be exploited in attacks.

The set of all possible keys that can be used in a cryptographic system.

Techniques used to analyze ciphertext for patterns or anomalies that can reveal information about the plaintext or the encryption method.

The mathematical rule used to transform plaintext into ciphertext and vice versa.

This principle states that the security of a cryptosystem should rely solely on the secrecy of the key, and not on the secrecy of the algorithm itself. The algorithm can be publicly known.

A type of symmetric cipher that encrypts data one bit or byte at a time. This makes it suitable for continuous data streams.

The primary goal of cryptanalysis is to break the encryption, either by recovering the plaintext from ciphertext or, more commonly, by recovering the secret key.